Most teachers would agree: being confronted with a pupil's pretend penis is uncomfortable to say the least. But that was the unenviable situation Robert* repeatedly found himself in.
As he walked up and down the classroom, one boy would grab anything he had to hand - rolled-up paper, pens, rubbers and rulers - and fashion the stationary into a phallus. The boy would then wrap his fingers round it and simulate masturbation.
"As I passed him, he'd frequently say, `Do you like the look of this?' with a smile on his face," says Robert, who was a young, inexperienced secondary school teacher in east London at the time.
Feeling embarrassed, he did not report the incident. "It turns out I should have told someone. The boy was later found out to be a victim of abuse."
It is not unusual for teachers to find themselves in these awkward scenarios. Low-level incidents may include pupils being inappropriately flirty with a teacher or revealing a relatively innocent crush. But cases of sexual harassment are not uncommon, either.
Almost 10 per cent of teachers have received threats of a sexual nature, according to a survey of 414 teachers by the Teacher Support Network (TSN) in June. Earlier research carried out by the University of Warwick for the National Union of Teachers (NUT) also confirmed that one teacher in 10 had experienced sexual harassment from pupils at some stage in their career.
Despite its prevalence, teachers and schools often ignore sexual bullying. Many simply dismiss it because they are too embarrassed to discuss it.
That was certainly the approach taken by Robert. When another of his pupils revealed that she wanted to cast him as the leading man in her latest erotic novel, he simply laughed it off and said she couldn't.
But other incidents are less easy to laugh off. The teaching union NASUWT regularly deals with cases of pupils who sexually bully their teachers. Some make sexual remarks; others have used their mobile phones to photograph a teacher's cleavage. A growing phenomenon is the posting of sexually explicit comments, pictures or allegations about teachers on the internet.
"Pupils can make these allegations under a cloak of anonymity, while the teacher is exposed to public ridicule and humiliation," says Chris Keates, general secretary of the NASUWT.
Experienced, confident teachers may feel more comfortable reporting this type of behaviour. But, although teachers of either sex or any age can become targets, pupils tend to prey on those they perceive as more vulnerable.
Younger, newly qualified female teachers and supply teachers are particularly at risk, says Kate Myers, who discusses sexual dynamics in her book Teachers Behaving Badly?
"It is already a major concern with the Fast Track students I work with," she says. "New teachers are all too aware that crushes can get out of hand, but they receive little or no training in how to deal with it."
Gay and lesbian teachers can also live in fear of being "outed" by their pupils. "Children can pick up on that fear and taunt them or spread rumours that may or may not be true," says Ms Myers. "Teachers often decide to leave the profession all together rather than risk being exposed against their will."
Some of the hardest situations to resolve are those that are not predatory or malicious, but still push the boundaries of acceptability. Ms Myers recalls a pupil who wore a suggestively low top in a male NQT's lessons, causing him to become jittery and awkward in her presence. Another pupil always opened the door for his female teacher with an ornate flourish. "It was chivalrous, courteous and threatening all at the same time," says Ms Myers. "It showed the teacher that he had the upper hand."
In extreme cases, this jostling for power can result in horrifying physical attacks. A female teacher received an undisclosed payment from her school in June, having been raped by a 15-year-old pupil in a classroom in 2004. She had been working at the London school for less than a week.
Schools cannot afford to take chances with the safety and wellbeing of its teachers, says Tom Bennett, head of religious studies and philosophy at Raine's Foundation School in Bethnal Green, east London, and resident behavioural expert on the TES website.
"I've known a teacher to be pushed up against a wall while a teenager grabbed her backside," he says. "I've also heard teachers being asked if they want to go out with pupils. It is a very real problem for a lot of teachers."
However, many teachers see it as a bit of a laugh rather than a threat to their authority. One teacher confessed to Mr Bennett that a Year 10 boy had put his hand on her knee during an after-school chat. Instead of removing his hand and reporting the incident, the female teacher blushed and giggled. "He was really good-looking," she explained.
Mr Bennett "nearly had a hernia" when he heard. He is aghast that some teachers should act in this way, not least because gossip and rumour can all too quickly lead to malicious allegations and immediate suspension.
"A lot of normally intelligent women think that giggling and making a saucy comment back is a good way of dealing with it," he says. "No, it bloody isn't - it's conforming to the oppressive, unnatural sexual scenario that the boy is conjuring up, and demeans the teacher in the eyes of every boy in that class.
"She's no long the authority; she's a piece of meat and she'll be lucky to get any respect from them ever again."
Ms Myers agrees that teachers should never do anything to imply that a crush is reciprocated, but adds that lines can get unintentionally blurred. As a small female teacher in the 1960s, she admits to having flirted with some of her rowdier 16-year-old boys as a form of behaviour management. She's sure other teachers, perhaps subconsciously, do the same in an effort to maintain control.
"Teachers can find compliments about their clothing, hair or make-up quite flattering," she says, "especially if the individual is naturally flirty without having any sexual intentions."
Others may be genuinely attracted to their charges. "We always think about these relationships occurring in cities, but in small villages with only one pub teachers may bump into their pupils on social occasions all the time.
"Outside of a school setting, no one would think twice if a 17-year-old started a relationship with a 22-year-old. But a teacher has a duty of care, and can't go there."
Muddying the waters still further are younger pupils who exhibit a sexuality far beyond their years. There are "worrying" levels of sexual behaviour in primary schools, according to an Ofsted enquiry in June. It uncovered examples of pupils as young as four who had been suspended for touching other children inappropriately and using sexually graphic language.
Parent support groups suggest that the increased prevalence of Playboy merchandise for children and lacy knickers for nine-year-olds - even pole- dancing kits in one supermarket - all encourage young people to present themselves in increasingly sexual terms. So it's not surprising if they are confused about how or when they should express themselves sexually, argues Mr Bennett.
"Teenagers now feel a lot less restricted from making the kind of cracks to women teachers that 40 years ago they would have been barely able to imagine," he says. "It's only a few, thankfully, but it's enough to make it an occupational hazard."
The so-called "ladette" culture also actively encourages assertive girls to gain the attention of older men by whatever means possible. "It's a challenge for them," says Ms Myers. "It's a game they have and they don't mind harassing a teacher in order to win."
Mark, a secondary school PGCE student, was shocked at how forward some girls can be. At one of his placement schools, girls would often comment on his appearance or ask him about his private life or relationship. "At first it scared me to death and I just froze, but now we have a bit of banter about it before getting on with the lesson," he says.
"It's a bit unnerving, but I think it's because they're prepared to push it further with a student. I don't think it will happen next year."
But more experienced teachers are also coming under fire. The NUT survey found that both younger and older female respondents identified sexual comments made to them by male pupils as a matter for concern.
One 40-year-old teacher told the TES Magazine that she had received a note in her bag from a boy which "suggested smut". Another pupil made a rap song in which he claimed he had "done her in the school hall". The song was then uploaded on to a social networking site and passed around pupils' MP3 players and mobile phones.
"As soon as I heard about it, I went to my senior management team," says the teacher. "They excluded him and he had to write a formal letter of apology. Even now the boy can't look me in the eye, and he was mocked by his peers for crap music and lyrics. In the end, I felt quite sorry for him."
Teachers usually expect a degree of sexual innuendo in the classroom, dismissing such hormone-fuelled behaviour as "quite normal". But pupils need to know where to draw the line, says Ms Myers. "If there is bad discipline in the school, any teacher can become a target at any point in their career."
If a teacher handles this unwanted attention unwisely, it can open the door to malicious allegations. One secondary school teacher laughed off rumours that a boy had a crush on her, telling pupils "he must have good taste".
She now receives mildly catty comments from both colleagues and pupils, which insinuate that she and the boy are "an item". She is increasingly worried that the boy may start to make things up or boast to his friends about their non-existent antics.
The statistics imply she is right to be concerned. In 1991, 44 allegations of physical or sexual abuse were levied against NASUWT members by pupils. In 2007, that figure more than quadrupled - up to 192 allegations, of which only seven have resulted in a caution or conviction. So what starts as a playful rumour could become something much more serious.
"By and large, the end result of such an allegation is a permanent blight on a teacher's career, and many leave the profession even when they are exonerated," says Ms Keates. Stress-induced breakdowns are not uncommon, she adds. Three have committed suicide in the past 20 years after physical or sexual allegations.
It is imperative, therefore, that any form of sexual harassment is nipped in the bud and dealt with professionally. Teachers need to put feelings of awkwardness to one side and report any incidents to their line managers, a spokesman from the Teacher Support Network says.
"You should ensure that you have information concerning the incident in writing, clearly outlining any situations, conversations or perceptions," he says. "If a pupil does then make false allegations against you, you will have some protection or evidence to demonstrate your side of the story."
Teachers who do find the courage to report an incident need to feel confident that something will be done about it - usually, that disciplinary procedures will be quickly implemented, along with a letter of apology. The NUT research found that only half of the serious incidents were reported to senior colleagues, either because teachers decided to deal with it themselves, or because whole-school support was seen as unsatisfactory.
Too many schools are ignoring sexual harassment or not taking it seriously enough, Ms Keates agrees. The failure to collect data on this form of bullying also means that schools are unaware of the extent of the problem.
All schools are required to have an anti-discrimination policy, which should include a clear statement outlining what sexual harassment is, plus the consequences for those who cross the line.
Any unwanted sexual act or language that is perceived as pejorative probably is, adds Ms Myers. The whole school community should then be involved in eradicating inappropriate behaviour, starting with contributions towards the creation or drafting of a policy.
"Involving the school council is a good way of seeing what's happening on the ground," she says. "Once schools have a better feeling for what's going on, they can take steps to stamp out predatory behaviour."
Extra training for student teachers is also needed, Ms Myers argues. Inexperienced teachers, generally closer in age to those they teach, should have a forum in which they can openly discuss boundaries, including those that involve pupils with a strong, genuine attraction.
But as society encourages, or at least condones, sexually active and explicit children, it may not be realistic for schools to take the moral high ground. One older female teacher told the NUT survey that residents of her local town saw little wrong with young people using sexually graphic language. "Some parents are poor role models," she says. "Pupils imitate the language and behaviour they see at home."
Another teacher has told the TES Magazine that parents often back their children even when they have been violent at school, so sexual innuendo is never going to raise an eyebrow. "Are they likely to be bothered by a few `jokey' remarks?" she asks.
Those who do report incidents can become the target of undermining gossip among parents and colleagues, she adds. "They may talk about how you haven't got a sense of humour, are oversensitive, neurotic or don't understand young people," she says.
By dismissing sexual harassment in this way, people are underestimating the seriousness of the offence, argues Mr Bennett. "It's one thing for a pupil to rebel against authority, but to actually make a sexually suggestive comment is an appalling leap into a whole other area of wrongdoing," he says.
"The pupil is not only suggesting that there is no boundary of authority between the young and the old, but is also attempting to create the idea that the pupil has sexual rights over the teacher."
Pupils may just be pushing their luck, trying to find out where the boundaries lie. It is up to schools and teachers to let them know, in no uncertain terms, exactly where those lines of acceptability are. Any residual confusion could ruin lives and careers for good.
*The teacher's name has been changed
How to respond to a pupil's advances
- If a pupil's behaviour or language is inappropriate or sexualised, discourage them and make sure you are never alone with them.
- Tell your line manager as soon as possible.
- Make a written record of what has happened, including dates and times; what you said to the pupil; who you spoke to after the event, and what advice you were given.
- Keep any notes, cards or emails from the pupil as evidence. Be especially alert to flirty messages on "red letter days" such as Valentine's Day, Christmas, Easter or your birthday.
- Remember that, under the Sexual Offences Act 2003, teachers are breaking the law if they start a relationship with one of their pupils, regardless of their age.